Size-selected clusters as heterogeneous model catalysts under applied reaction conditions.

First results of investigations are presented, where size-selected metal clusters generated in ultra high vacuum (UHV) are transferred to ambient conditions and tested for suitable electrochemical applications. As demonstrated, the transfer allows for the characterization of clusters by transmission electron microscopy (TEM) as well as catalytic measurements, which is exemplified by the application of electrochemical measurements. It is demonstrated that well known electrochemical processes on the carbon supported Pt clusters are detected, and thus Pt clusters can be characterized with respect to their accessible surface area, an essential requirement for the study of catalytic processes. Furthermore, as an example for an important electrocatalytic process, it is shown that the oxygen reduction reaction can be probed on the cluster samples featuring a detrimental particle size effect, previously reported for industrial catalysts as well.